Electronic systems and processor-based systems

ABSTRACT

A magnetic cell includes a free region between an intermediate oxide region (e.g., a tunnel barrier) and a secondary oxide region. Both oxide regions may be configured to induce magnetic anisotropy (“MA”) with the free region, enhancing the MA strength of the free region. A getter material proximate to the secondary oxide region is formulated and configured to remove oxygen from the secondary oxide region, reducing an oxygen concentration and an electrical resistance of the secondary oxide region. Thus, the secondary oxide region contributes only minimally to the electrical resistance of the cell core. Embodiments of the present disclosure therefore enable a high effective magnetoresistance, low resistance area product, and low programming voltage along with the enhanced MA strength. Methods of fabrication, memory arrays, memory systems, and electronic systems are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/000,272, filed Jun. 5, 2018, pending, which is a continuation of U.S.patent application Ser. No. 15/239,481, filed Aug. 17, 2016, now U.S.Pat. No. 10,020,446, issued Jul. 10, 2018, which is a divisional of U.S.patent application Ser. No. 14/026,627, filed Sep. 13, 2013, now U.S.Pat. No. 9,461,242, issued Oct. 4, 2016, the disclosure of each of whichis hereby incorporated in its entirety herein by this reference.

TECHNICAL FIELD

The present disclosure, in various embodiments, relates generally to thefield of memory device design and fabrication. More particularly, thisdisclosure relates to design and fabrication of memory cellscharacterized as spin torque transfer magnetic random access memory(STT-MRAM) cells.

BACKGROUND

Magnetic Random Access Memory (MRAM) is a non-volatile computer memorytechnology based on magnetoresistance. One type of MRAM cell is a spintorque transfer MRAM (STT-MRAM) cell, which includes a magnetic cellcore supported by a substrate. The magnetic cell core includes at leasttwo magnetic regions, for example, a “fixed region” and a “free region,”with a non-magnetic region (e.g., an oxide region configured as a tunnelbarrier region) between. The free regions and fixed regions may exhibitmagnetic orientations that are either horizontally oriented (“in-plane”)or perpendicularly oriented (“out-of-plane”) with the width of theregions. The fixed region includes a magnetic material that has asubstantially fixed (e.g., a non-switchable) magnetic orientation. Thefree region, on the other hand, includes a magnetic material that has amagnetic orientation that may be switched, during operation of the cell,between a “parallel” configuration and an “anti-parallel” configuration.In the parallel configuration, the magnetic orientations of the fixedregion and the free region are directed in the same direction (e.g.,north and north, east and east, south and south, or west and west,respectively). In the “anti-parallel” configuration the magneticorientations of the fixed region and the free region are directed inopposite directions (e.g., north and south, east and west, south andnorth, or west and east, respectively). In the parallel configuration,the STT-MRAM cell exhibits a lower electrical resistance across themagnetoresistive elements (e.g., the fixed region and free region). Thisstate of low electrical resistance may be defined as a “0” logic stateof the MRAM cell. In the anti-parallel configuration, the STT-MRAM cellexhibits a higher electrical resistance across the magnetoresistiveelements. This state of high electrical resistance may be defined as a“1” logic state of the STT-MRAM cell.

Switching of the magnetic orientation of the free region may beaccomplished by passing a programming current through the magnetic cellcore and the fixed and free regions therein. The fixed region polarizesthe electron spin of the programming current, and torque is created asthe spin-polarized current passes through the core. The spin-polarizedelectron current exerts the torque on the free region. When the torqueof the spin-polarized electron current passing through the core isgreater than a critical switching current density (J_(c)) of the freeregion, the direction of the magnetic orientation of the free region isswitched. Thus, the programming current can be used to alter theelectrical resistance across the magnetic regions. The resulting high orlow electrical resistance states across the magnetoresistive elementsenable the write and read operations of the MRAM cell. After switchingthe magnetic orientation of the free region to achieve the one of theparallel configuration and the anti-parallel configuration associatedwith a desired logic state, the magnetic orientation of the free regionis usually desired to be maintained, during a “storage” stage, until theMRAM cell is to be rewritten to a different configuration (i.e., to adifferent logic state).

Some STT-MRAM cells include, in addition to the oxide region (the“intermediate oxide region”) between the free region and the fixedregion, another oxide region. The free region may be between theintermediate oxide region and the another oxide region. The exposure ofthe free region to two oxide regions may increase the free region'smagnetic anisotropy (“MA”) strength. For example, the oxide regions maybe configured to induce surface/interfacial MA with neighboring materialof, e.g., the free region. MA is an indication of the directionaldependence of a magnetic material's magnetic properties. Therefore, theMA is also an indication of the strength of the material's magneticorientation and of its resistance to alteration of the magneticorientation. A magnetic material exhibiting a magnetic orientation witha high MA strength may be less prone to alteration of its magneticorientation than a magnetic material exhibiting a magnetic orientationwith a lower MA strength. Therefore, a free region with a high MAstrength may be more stable during storage than a free region with a lowMA strength.

While the dual oxide regions may increase the MA strength of the freeregion, compared to a free region adjacent to only one oxide region(i.e., the intermediate oxide region), the added amount of oxidematerial in the magnetic cell core may increase the electricalresistance (e.g., the series resistance) of the core, which lowers theeffective magnetoresistance (e.g., tunnel magnetoresistance) of thecell, compared to a cell core comprising only one oxide region (i.e.,the intermediate oxide region). The increased electrical resistance alsoincreases the resistance-area (“RA”) of the cell and may increase thevoltage needed to switch the magnetic orientation of the free regionduring programming. The decreased effective magnetoresistance maydegrade performance of the cell, as may the increased RA and programmingvoltage. Accordingly, forming STT-MRAM cells to have dual oxide regionsaround the free region, for high MA strength, without degrading otherproperties, such as magnetoresistance (e.g., tunnel magnetoresistance),RA, and programming voltage, has presented challenges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional, elevational, schematic illustration of amagnetic cell structure according to an embodiment of the presentdisclosure, wherein a getter region is adjacent to a base oxide region.

FIG. 1A is an enlarged view of box AB of FIG. 1, according to anembodiment of the present disclosure in which a free region and a fixedregion of the magnetic cell structure of FIG. 1 exhibit perpendicularmagnetic orientations.

FIG. 1B is an enlarged view of box AB of FIG. 1, according to anembodiment of the present disclosure in which a free region and a fixedregion of the magnetic cell structure of FIG. 1 exhibit horizontalmagnetic orientations.

FIG. 2 is a cross-sectional, elevational, schematic illustration of amagnetic cell structure according to an embodiment of the presentdisclosure, wherein a getter region is within a base oxide region.

FIG. 3 is a partial, cross-sectional, elevational, schematicillustration of a magnetic cell structure during a stage of processing,prior to transfer of oxygen from an oxide region to a proximate getterregion.

FIG. 4 is a partial, cross-sectional, elevational, schematicillustration of a magnetic cell structure during a stage of processingfollowing that of FIG. 3 and following transfer of oxygen from the oxideregion to the proximate getter region.

FIG. 5 is a cross-sectional, elevational, schematic illustration of amagnetic cell structure according to an embodiment of the presentdisclosure, wherein a getter region is adjacent and above a cap oxideregion that is above a free region.

FIG. 6 is a partial, cross-sectional, elevational, schematicillustration of a magnetic cell structure according to an embodiment ofthe present disclosure, wherein a getter region is indirectly adjacentto a base oxide region.

FIG. 7 is a partial, cross-sectional, elevational, schematicillustration of a magnetic cell structure according to an embodiment ofthe present disclosure, wherein a getter region laterally surrounds abase oxide region.

FIG. 8 is a plan view of the structure of FIG. 7 taken along sectionline 8-8.

FIG. 9 is a schematic diagram of an STT-MRAM system including a memorycell having a magnetic cell structure according to an embodiment of thepresent disclosure.

FIG. 10 is a simplified block diagram of a semiconductor devicestructure including memory cells having a magnetic cell structureaccording to an embodiment of the present disclosure.

FIG. 11 is a simplified block diagram of a system implemented accordingto one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

Memory cells, methods of forming memory cells, semiconductor devices,memory systems, and electronic systems are disclosed. The memory cellsinclude a magnetic region (e.g., a free region), formed from a magneticmaterial, between two oxide regions, both of which may be magneticanisotropy (“MA”)-inducing regions. One of the oxide regions, e.g.,positioned between the free region and another magnetic region (e.g., afixed region) and referred to herein as the “intermediate oxide region,”may be configured to function as a tunnel barrier of the memory cell.The other oxide region, referred to herein as the “secondary oxideregion,” may not be configured to function as a tunnel barrier. A gettermaterial is proximate to the secondary oxide region and is formulated toremove oxygen from the secondary oxide region, reducing the electricalresistance of the secondary oxide region and, thus, avoiding substantiallowering of the effective magnetoresistance of the memory cell. Theelectrical resistance of the secondary oxide region may be less thanabout 50% (e.g., between about 1% and about 20%) of the electricalresistance of the intermediate oxide region. In some embodiments, thesecondary oxide region may become electrically conductive as a result ofthe removal of oxygen by the getter material. The overall electricalresistance of the STT-MRAM cell may, therefore, be decreased compared toan STT-MRAM cell lacking the getter material proximate the secondaryoxide region. Further, the decreased electrical resistance avoidsdegradation to the magnetoresistance of the cell; thus, the STT-MRAMcell with getter material proximate the secondary oxide region may havea higher effective magnetoresistance compared to an STT-MRAM celllacking such a getter material region. Nonetheless, the two oxideregions of the getter-including STT-MRAM cell may still induce MA withthe free region. Therefore, the MA strength may not be degraded, whilethe electrical resistance is decreased to enable a maximum tunnelingmagnetoresistance, a low resistance area (“RA”) product, and use of alow programming voltage.

As used herein, the term “substrate” means and includes a base materialor other construction upon which components, such as those within memorycells, are formed. The substrate may be a semiconductor substrate, abase semiconductor material on a supporting structure, a metalelectrode, or a semiconductor substrate having one or more materials,structures, or regions formed thereon. The substrate may be aconventional silicon substrate or other bulk substrate including asemiconductive material. As used herein, the term “bulk substrate” meansand includes not only silicon wafers, but also silicon-on-insulator(“SOI”) substrates, such as silicon-on-sapphire (“SOS”) substrates orsilicon-on-glass (“SOG”) substrates, epitaxial layers of silicon on abase semiconductor foundation, or other semiconductor or optoelectronicmaterials, such as silicon-germanium (Si_(1-x)Ge_(x), where x is, forexample, a mole fraction between 0.2 and 0.8), germanium (Ge), galliumarsenide (GaAs), gallium nitride (GaN), or indium phosphide (InP), amongothers. Furthermore, when reference is made to a “substrate” in thefollowing description, previous process stages may have been utilized toform materials, regions, or junctions in the base semiconductorstructure or foundation.

As used herein, the term “STT-MRAM cell” means and includes a magneticcell structure that includes a magnetic cell core including anonmagnetic region disposed between a free region and a fixed region.The STT-MRAM cell may be configured in a magnetic tunnel junction(“MTJ”) configuration, in which the nonmagnetic region comprises anelectrically insulative (e.g., dielectric) material, such as an oxide.Such an electrically-insulative, oxide, nonmagnetic region, disposedbetween a free region and a fixed region, is referred to herein as an“intermediate oxide region.”

As used herein, the term “magnetic cell core” means and includes amemory cell structure comprising the free region and the fixed regionand through which, during use and operation of the memory cell, currentmay be passed (i.e., flowed) to effect a parallel or anti-parallelconfiguration of the magnetic orientations of the free region and thefixed region.

As used herein, the term “magnetic region” means a region that exhibitsmagnetism. A magnetic region includes a magnetic material and may alsoinclude one or more non-magnetic materials.

As used herein, the term “magnetic material” means and includesferromagnetic materials, ferrimagnetic materials, antiferromagnetic, andparamagnetic materials.

As used herein, the term “CoFeB material” means and includes a materialcomprising cobalt (Co), iron (Fe), and boron (B) (e.g.,Co_(x)Fe_(y)B_(z), wherein x=10 to 80, y=10 to 80, and z=0 to 50). ACoFeB material may or may not exhibit magnetism, depending on itsconfiguration (e.g., its thickness).

As used herein, the term “fixed region” means and includes a magneticregion within the STT-MRAM cell that includes a magnetic material andthat has a fixed magnetic orientation during use and operation of theSTT-MRAM cell in that a current or applied field effecting a change inthe magnetization direction of one magnetic region, e.g., the freeregion, of the cell core may not effect a change in the magnetizationdirection of the fixed region. The fixed region may include one or moremagnetic materials and, optionally, one or more non-magnetic materials.For example, the fixed region may be configured as a syntheticantiferromagnet (SAF) including a sub-region of ruthenium (Ru) adjoinedby magnetic sub-regions. Each of the magnetic sub-regions may includeone or more materials and one or more regions therein. As anotherexample, the fixed region may be configured as a single, homogeneousmagnetic material. Accordingly, the fixed region may have uniformmagnetization, or sub-regions of differing magnetization that, overall,effect the fixed region having a fixed magnetic orientation during useand operation of the STT-MRAM cell.

As used herein, the term “free region” means and includes a magneticregion within the STT-MRAM cell that includes a magnetic material andthat has a switchable magnetic orientation during use and operation ofthe STT-MRAM cell. The magnetic orientation may be switched between aparallel configuration and an anti-parallel configuration by theapplication of a current or applied field.

As used herein, “switching” means and includes a stage of use andoperation of the memory cell during which programming current is passedthrough the magnetic cell core of the STT-MRAM cell to effect a parallelor anti-parallel configuration of the magnetic orientations of the freeregion and the fixed region.

As used herein, “storage” means and includes a stage of use andoperation of the memory cell during which programming current is notpassed through the magnetic cell core of the STT-MRAM cell and in whichthe parallel or anti-parallel configuration of the magnetic orientationsof the free region and the fixed region is not purposefully altered.

As used herein, the term “vertical” means and includes a direction thatis perpendicular to the width and length of the respective region.“Vertical” may also mean and include a direction that is perpendicularto a primary surface of the substrate on which the STT-MRAM cell islocated.

As used herein, the term “horizontal” means and includes a directionthat is parallel to at least one of the width and length of therespective region. “Horizontal” may also mean and include a directionthat is parallel to a primary surface of the substrate on which theSTT-MRAM cell is located.

As used herein, the term “sub-region,” means and includes a regionincluded in another region. Thus, one magnetic region may include one ormore magnetic sub-regions, i.e., sub-regions of magnetic material, aswell as non-magnetic sub-regions, i.e., sub-regions of non-magneticmaterial.

As used herein, the term “between” is a spatially relative term used todescribe the relative disposition of one material, region, or sub-regionrelative to at least two other materials, regions, or sub-regions. Theterm “between” can encompass both a disposition of one material, region,or sub-region directly adjacent to the other materials, regions, orsub-regions and a disposition of one material, region, or sub-regionindirectly adjacent to the other materials, regions, or sub-regions.

As used herein, the term “proximate to” is a spatially relative termused to describe disposition of one material, region, or sub-region nearto another material, region, or sub-region. The term “proximate”includes dispositions of indirectly adjacent to, directly adjacent to,and internal to.

As used herein, reference to an element as being “on” or “over” anotherelement means and includes the element being directly on top of,adjacent to, underneath, or in direct contact with the other element. Italso includes the element being indirectly on top of, adjacent to,underneath, or near the other element, with other elements presenttherebetween. In contrast, when an element is referred to as being“directly on” or “directly adjacent to” another element, there are nointervening elements present.

As used herein, other spatially relative terms, such as “beneath,”“below,” “lower,” “bottom,” “above,” “upper,” “top,” “front,” “rear,”“left,” “right,” and the like, may be used for ease of description todescribe one element's or feature's relationship to another element(s)or feature(s) as illustrated in the figures. Unless otherwise specified,the spatially relative terms are intended to encompass differentorientations of the materials in addition to the orientation as depictedin the figures. For example, if materials in the figures are inverted,elements described as “below” or “beneath” or “under” or “on bottom of”other elements or features would then be oriented “above” or “on top of”the other elements or features. Thus, the term “below” can encompassboth an orientation of above and below, depending on the context inwhich the term is used, which will be evident to one of ordinary skillin the art. The materials may be otherwise oriented (rotated 90 degrees,inverted, etc.) and the spatially relative descriptors used hereininterpreted accordingly.

As used herein, the terms “comprises,” “comprising,” “includes,” and/or“including” specify the presence of stated features, regions, integers,stages, operations, elements, materials, components, and/or groups, butdo not preclude the presence or addition of one or more other features,regions, integers, stages, operations, elements, materials, components,and/or groups thereof.

As used herein, “and/or” includes any and all combinations of one ormore of the associated listed items.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

The illustrations presented herein are not meant to be actual views ofany particular component, structure, device, or system, but are merelyidealized representations that are employed to describe embodiments ofthe present disclosure.

Embodiments are described herein with reference to cross-sectionalillustrations that are schematic illustrations. Accordingly, variationsfrom the shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,embodiments described herein are not to be construed as limited to theparticular shapes or regions as illustrated but may include deviationsin shapes that result, for example, from manufacturing techniques. Forexample, a region illustrated or described as box-shaped may have roughand/or nonlinear features. Moreover, sharp angles that are illustratedmay be rounded. Thus, the materials, features, and regions illustratedin the figures are schematic in nature and their shapes are not intendedto illustrate the precise shape of a material, feature, or region and donot limit the scope of the present claims.

The following description provides specific details, such as materialtypes and processing conditions, in order to provide a thoroughdescription of embodiments of the disclosed devices and methods.However, a person of ordinary skill in the art will understand that theembodiments of the devices and methods may be practiced withoutemploying these specific details. Indeed, the embodiments of the devicesand methods may be practiced in conjunction with conventionalsemiconductor fabrication techniques employed in the industry.

The fabrication processes described herein do not form a completeprocess flow for processing semiconductor device structures. Theremainder of the process flow is known to those of ordinary skill in theart. Accordingly, only the methods and semiconductor device structuresnecessary to understand embodiments of the present devices and methodsare described herein.

Unless the context indicates otherwise, the materials described hereinmay be formed by any suitable technique including, but not limited to,spin coating, blanket coating, chemical vapor deposition (“CVD”), atomiclayer deposition (“ALD”), plasma enhanced ALD, physical vapor deposition(“PVD”), or epitaxial growth. Depending on the specific material to beformed, the technique for depositing or growing the material may beselected by a person of ordinary skill in the art.

Unless the context indicates otherwise, the removal of materialsdescribed herein may be accomplished by any suitable techniqueincluding, but not limited to, etching, ion milling, abrasiveplanarization, or other known methods.

Reference will now be made to the drawings, where like numerals refer tolike components throughout. The drawings are not necessarily drawn toscale.

A memory cell is disclosed. The memory cell includes a magnetic cellcore that includes a free region located between two oxide regions,including an intermediate oxide region and a secondary oxide region.Both regions may be configured to induce MA (magnetic anisotropy) withthe free region. The intermediate oxide region may also be configured tofunction as a tunnel barrier. A getter material is proximate to thesecondary oxide region. The getter material has a chemical affinity foroxygen that is greater than or about equal to the chemical affinity foroxygen of the oxide material of the secondary oxide region. For example,the getter material may be formed of a metal for which the heat offormation of a metal oxide from the metal is lower than (e.g., morenegative than) the heat of formation of the oxide of the secondary oxideregion. Accordingly, the getter material is formulated to remove oxygenfrom the secondary oxide region, reducing the concentration of oxygenwithin the secondary oxide region and, therefore, reducing theelectrical resistance of the secondary oxide region. The reduction inelectrical resistance enables a higher magnetoresistance, a lower RA(resistance area) product, and a lower programming voltage, compared toan STT-MRAM cell without the getter matter. Therefore, the STT-MRAM cellmay be formed to include two MA-inducing regions, providing high MAstrength, without degrading tunneling magnetoresistance, RA product, orthe programming voltage.

FIG. 1 illustrates an embodiment of a magnetic cell structure 100according to the present disclosure. The magnetic cell structure 100includes a magnetic cell core 101 over a substrate 102. The magneticcell core 101 may be disposed between an upper electrode 104 above and alower electrode 105 below. A conductive material, from which either orboth of the upper electrode 104 and the lower electrode 105 are formed,may comprise, consist essentially of, or consist of, for example andwithout limitation, a metal (e.g., copper, tungsten, titanium,tantalum), a metal alloy, or a combination thereof.

The magnetic cell core 101 includes at least two magnetic regions, forexample, a “fixed region” 110 and a “free region” 120. The free region120 and the fixed region 110 may be formed from, comprise, consistessentially of, or consist of ferromagnetic materials, such as Co, Fe,Ni or their alloys, NiFe, CoFe, CoNiFe, or doped alloys CoX, CoFeX,CoNiFeX (X=B, Cu, Re, Ru, Rh, Hf, Pd, Pt, C), or other half-metallicferromagnetic materials, such as, for example, NiMnSb and PtMnSb. Insome embodiments, for example, the free region 120, the fixed region110, or both may be formed, in whole or in part, from Co_(x)Fe_(y)B_(z),wherein x=10 to 80, y=10 to 80, and z=0 to 50. In other embodiments, thefree region 120, the fixed region 110, or both may be formed, in wholeor in part, of iron (Fe) and boron (B) and not include cobalt (Co). Thecompositions and structures (e.g., the thicknesses and other physicaldimensions) of the free region 120 and the fixed region 110 may be thesame or different.

Alternatively or additionally, in some embodiments, the free region 120,the fixed region 110, or both, may be formed from or comprise aplurality of materials, some of which may be magnetic materials and someof which may be nonmagnetic materials. For example, some suchmulti-material free regions, fixed regions, or both, may includemultiple sub-regions. For example, and without limitation, the freeregion 120, the fixed region 110, or both, may be formed from orcomprise repeating sub-regions of cobalt and platinum, wherein asub-region of platinum may be disposed between sub-regions of cobalt. Asanother example, without limitation, the free region 120, the fixedregion 110, or both, may comprise repeating sub-regions of cobalt andnickel, wherein a sub-region of nickel may be disposed betweensub-regions of cobalt. Thus, either or both of the fixed region 110 andthe free region 120 may be formed homogeneously or, optionally, may beformed to include more than one sub-region of magnetic material and,optionally, nonmagnetic material (e.g., coupler material).

In some embodiments, both the fixed region 110 and the free region 120may be formed, in whole or in part, from the same material, e.g., aCoFeB material. However, in some such embodiments, the relative atomicratios of Co:Fe:B may be different in the fixed region 110 and the freeregion 120. One or both of the fixed region 110 and the free region 120may include sub-regions of magnetic material that include the sameelements as one another, but with different relative atomic ratios ofthe elements therein. For example, and without limitation, a sub-regionof the free region 120 may have a lower concentration of boron (B)compared to CoFe than another sub-region of the free region 120.

In some embodiments, the memory cells of embodiments of the presentdisclosure may be configured as out-of-plane STT-MRAM cells.“Out-of-plane” STT-MRAM cells, include magnetic regions exhibiting amagnetic orientation that is predominantly oriented in a verticaldirection. For example, as illustrated in FIG. 1A, which is a view ofbox AB of FIG. 1, the STT-MRAM cell may be configured to exhibit avertical magnetic orientation in at least one of the magnetic regions(e.g., the fixed region 110 and the free region 120). The verticalmagnetic orientation exhibited may be characterized by perpendicularmagnetic anisotropy (“PMA”) strength. As illustrated in FIG. 1A byarrows 112A and double-pointed arrows 122A, in some embodiments, each ofthe fixed region 110 and the free region 120 may exhibit a verticalmagnetic orientation. The magnetic orientation of the fixed region 110may remain directed in essentially the same direction throughoutoperation of the STT-MRAM cell, for example, in the direction indicatedby arrows 112A of FIG. 1A. The magnetic orientation of the free region120, on the other hand, may be switched, during operation of the cell,between a parallel configuration and an anti-parallel configuration, asindicated by double-pointed arrows 122A of FIG. 1A.

In other embodiments, the memory cells of embodiments of the presentdisclosure may be configured as in-plane STT-MRAM cells. “In-plane”STT-MRAM cells include magnetic regions exhibiting a magneticorigination that is predominantly oriented in a horizontal direction.For example, as illustrated in FIG. 1B, which is a view of box AB ofFIG. 1, the STT-MRAM cell may be configure to exhibit a horizontalmagnetic orientation in at least one of the magnetic regions (e.g., thefixed region 110 and the free region 120). The horizontal orientationexhibited may be characterized by horizontal magnetic anisotropy (“HMA”)strength. As illustrated in FIG. 1B by arrows 112E and double-pointedarrows 122B, in some embodiments, each of the fixed region 110 and thefree region 120 may exhibit a horizontal magnetic orientation. Themagnetic orientation of the fixed region 110 may remain directed inessentially the same direction throughout operation of the STT-MRAMcell, for example, in the direction indicated by arrows 112E of FIG. 1B.The magnetic orientation of the free region 120, on the other hand, maybe switched, during operation of the cell, between a parallelconfiguration and an anti-parallel configuration, as indicated bydouble-pointed arrows 122E of FIG. 1B.

With continued reference to FIG. 1, an intermediate oxide region 130 maybe disposed between the free region 120 and the fixed region 110. Theintermediate oxide region 130 may be configured as a tunnel region andmay contact the fixed region 110 along interface 131 and may contact thefree region 120 along interface 132. The intermediate oxide region 130may be formed from, comprise, consist essentially of, or consist of anonmagnetic oxide material, e.g., magnesium oxide (MgO), aluminum oxide(Al₂O₃), titanium oxide (TiO₂), or other oxide materials of conventionaltunnel barrier regions. One or more nonmagnetic oxide materials may beincluded. In some embodiments, additional non-oxide materials may beincluded. The intermediate oxide region 130 may, thus, be formed as ahomogeneous region or as a region with a heterogeneous mixture ordistinctive sub-regions of one or more materials.

One or more lower intermediary regions 140 may, optionally, be disposedover the lower electrode 105 and under the fixed region 110 and the freeregion 120. The lower intermediary regions 140 may include foundationmaterials formulated and configured to provide a smooth template uponwhich overlying materials are formed and to enable formation ofoverlying materials at desired crystalline structures. The lowerintermediary regions 140 may alternatively or additionally includematerial configured to inhibit diffusion, during operation of the memorycell, between the lower electrode 105 and material overlying the lowerintermediary regions 140. For example, and without limitation, the lowerintermediary regions 140 may be formed from, comprise, consistessentially of, or consist of a material comprising at least one ofcobalt (Co) and iron (Fe) (e.g., a CoFeB material); a nonmagneticmaterial (e.g., a metal (e.g., tantalum (Ta), titanium (Ti), ruthenium(Ru), tungsten (W)), a metal nitride (e.g., tantalum nitride (TaN),titanium nitride (TiN)), a metal alloy); or any combination thereof. Insome embodiments, the lower intermediary regions 140, if included, maybe incorporated with the lower electrode 105. For example, the lowerintermediary regions 140 may include or consist of an upper-mostsub-region of the lower electrode 105.

One or more upper intermediary regions 150 may, optionally, be disposedover the magnetic regions (e.g., the fixed region 110 and the freeregion 120) of the magnetic cell core 101. The upper intermediaryregions 150, if included, may be configured to ensure a desired crystalstructure in neighboring materials, to aid in patterning processesduring fabrication of the magnetic cell, or to function as a diffusionbarrier. In some embodiments, the upper intermediary regions 150, ifpresent, may be formed from, comprise, consist essentially of, orconsist of a conductive material (e.g., one or more materials such ascopper (Cu), tantalum (Ta), titanium (Ti), tungsten (W), ruthenium (Ru),tantalum nitride (TaN), or titanium nitride Ta(N)). In some embodiments,the upper intermediary regions 150, if included, may be incorporatedwith the upper electrode 104. For example, the upper intermediaryregions 150 may include or consist of a lower-most sub-region of theupper electrode 104.

The magnetic cell core 101 also includes a secondary oxide region 170adjacent to the free region 120. The secondary oxide region 170 may beformed over the lower electrode 105 and, if present, the lowerintermediary regions 140. The secondary oxide region 170 may be formedfrom, comprise, consist essentially of, or consist of, for example andwithout limitation, a nonmagnetic oxide material (e.g., magnesium oxide(MgO), aluminum oxide (Al₂O₃), titanium oxide (TiO₂), or other oxidematerials of conventional tunnel barrier regions). In some embodiments,the secondary oxide region 170 may be formed from the same material fromwhich the intermediate oxide region 130 is formed, though the relativeatomic ratios of the elements of such material may be different in thesecondary oxide region 170 and the intermediate oxide region 130. Forexample, both the secondary oxide region 170 and the intermediate oxideregion 130 may be formed from MgO. However, as discussed below, thesecondary oxide region 170 may have a lower oxygen concentration thanthe intermediate oxide region 130.

A getter region 180 is formed proximate to the secondary oxide region170. In some embodiments, as illustrated in FIG. 1, the getter region180 may be adjacent (e.g., directly below) the secondary oxide region170. Thus, while the secondary oxide region 170 may be adjacent to thefree region 120 along an upper surface, e.g., at interface 172, thesecondary oxide region 170 may be adjacent to the getter region 180along an opposite, lower surface, e.g., at interface 178.

The getter region 180 is formulated and configured to remove oxygen fromthe secondary oxide region 170 so as to lower the oxygen concentrationin, and thus the electrical resistance of, the secondary oxide region170, which maximizes the magnetoresistance of the magnetic cell core101. For example, the getter region 180 may be formed from, comprise,consist essentially of, or consist of a material having a chemicalaffinity for oxygen that is about equal to or greater than the chemicalaffinity for oxygen of the material of the secondary oxide region 170,such that the material of the getter region 180 (referred to herein asthe “getter material”) is formulated to compete for the oxygen of thesecondary oxide region 170. In embodiments in which the getter materialincludes a metal, the metal-oxide heat of formation is an indication ofthe chemical affinity of the getter material for oxygen. Therefore, thegetter material of the getter region 180 may have a metal-oxide heat offormation that is about the same as (e.g., not greater than about 10%higher than) or less than the heat of formation of the oxide of thesecondary oxide region 170.

For example, and without limitation, in embodiments in which thesecondary oxide region 170 is formed of magnesium oxide (MgO), which hasa metal-oxide heat of formation of about −6.29 (eV), the getter materialof the getter region 180 may be formed from, comprise, consistessentially of, or consist of a metal having a metal-oxide heat offormation of equal to or less than about −5.66 (eV), e.g., calcium (Ca),strontium (Sr), aluminum (Al), barium (Ba), zirconium (Zr), compoundsthereof, or combinations thereof. Calcium oxide (CaO) has a metal-oxideheat of formation of about −6.58 (eV) (i.e., less than the heat offormation of MgO). Strontium oxide (SrO) has a metal-oxide heat offormation of about −6.13 (eV) (i.e., only about 2.5% higher than theheat of formation of MgO). Aluminum oxide (Al₂O₃) has a metal-oxide heatof formation of about −5.79 (eV) (i.e., only about 7.9% higher than theheat of formation of MgO). Barium oxide (BaO) and zirconium oxide (ZrO₂)have metal-oxide heats of formation of about −5.68 (eV) (i.e., onlyabout 9.7% higher than the heat of formation of MgO). Thus, the gettermaterial of the getter region 180 may be selected to compete for oxygenwith the material of the secondary oxide region 170.

The getter region 180 may be formed as a homogeneous region of a pure,elemental metal having the desired chemical affinity (e.g., metal-oxideheat of formation) for oxygen or of a compound of such metal. Forexample, in embodiments in which the secondary oxide region 170 isformed of magnesium oxide (MgO), the getter region 180 may be formedfrom pure calcium (Ca) or from a calcium compound (e.g., calciumcarbonate (CaCO₃)). In other embodiments, the getter region 180 mayinclude the getter material (e.g., the metal) embedded in a carriermaterial, e.g., magnesium oxide (MgO), titanium oxide (TiO). However, itis contemplated that the getter region 180 may be formulated andconfigured to provide sufficient free (i.e., available for chemicalreaction and/or bonding with oxygen) metal atoms to accomplishattraction and removal of oxygen from the secondary oxide region 170 toeffect a reduction in the oxygen concentration of and the electricalresistance of the secondary oxide region 170. For example, the getterregion 180 may be formulated to include a concentration of free metaland may be configured to have an amount (e.g., thickness) that enablesremoval of a desired amount of oxygen from the secondary oxide region170. In embodiments in which the concentration of free metal in thegetter material is low, the getter region 180 may be formed to be thick;whereas, in embodiments in which the concentration of free metal in thegetter material is high, the getter region 180 may be formed to be thinto accomplish the same removal of oxygen from the secondary oxide region170.

The removal of oxygen from the secondary oxide region 170 by the getterregion 180 may be initiated by annealing the materials of the magneticcell core 101 during fabrication thereof. In such embodiments, thetemperature and time of the anneal, which may be carried out in one ormore stages, may be tailored to achieve a desired transfer of oxygenfrom the secondary oxide region 170 to the getter region 180. Higheranneal temperatures and longer anneal times may promote more oxygenremoval compared to lower anneal temperatures and shorter anneal times.It is contemplated that the transfer of oxygen from the secondary oxideregion 170 to the getter region 180 be substantially permanent, suchthat, once transferred, oxygen may not diffuse back to the secondaryoxide region 170.

At least in embodiments in which the intermediate oxide region 130 andthe secondary oxide region 170 are formed from the same oxide material(e.g., MgO), the resulting magnetic cell core 101, after transfer ofoxygen between the secondary oxide region 170 and the getter region 180,includes the secondary oxide region 170 that has a lower concentrationof oxygen compared to the intermediate oxide region 130. In this orother embodiments, the secondary oxide region 170 has a lower electricresistance compared to the intermediate oxide region 130. For example,and without limitation, the secondary oxide region 170 may have anelectrical resistance that is less than about 50% (e.g., between about1% and about 20%) of the electrical resistance of the intermediate oxideregion 130. In some embodiments, the secondary oxide region 170 may beelectrically conductive as a result of the oxygen removal. Thus, asdescribed herein, the secondary oxide region 170 may be electricallyresistive, though less so than the intermediate oxide region 130, or maybe electrically conductive, both alternatives encompassed by thedescription of “lower electrical resistance,” as used herein. Thus, thesecondary oxide region 170 does not degrade (e.g., substantiallydecrease) the magnetoresistance of the cell.

Not all of the oxygen in the secondary oxide region 170 may be removedby the getter region 180. Rather, the getter region 180 may beformulated and configured to remove only a portion of the oxygen, toleave a minimal oxygen concentration in the secondary oxide region 170.It is contemplated that the minimal oxygen concentration is aconcentration sufficient to enable the secondary oxide region 170 tocontinue to induce surface/interface MA with the free region 120. Insome embodiments, the resulting, lowered oxygen concentration in thesecondary oxide region 170 may be consistent throughout the secondaryoxide region 170. In other embodiments, the secondary oxide region 170may have a gradient of oxygen, after the transfer of oxygen from thesecondary oxide region 170 to the getter region 180. Such oxygengradient may include a greater concentration proximate to the interface172 with the free region 120 and a lesser oxygen concentration proximateto the interface 178 with the getter region 180. In such embodiments,the oxygen concentration may subsequently equilibrate to asubstantially-consistent oxygen concentration throughout the secondaryoxide region 170.

It is contemplated that the getter region 180 be physically isolatedfrom the intermediate oxide region 130 to inhibit the getter region 180from removing oxygen from and lowering the oxygen concentration of theintermediate oxide region 130. Therefore, as illustrated in FIG. 1, thegetter region 180 may be spaced from the intermediate oxide region 130by other regions of the magnetic cell core 101, including, for exampleand without limitation, the secondary oxide region 170 and the freeregion 120. In such embodiments, the getter region 180 may notchemically interact with the intermediate oxide region 130.

In one embodiment of the present disclosure, the magnetic cell structure100 includes the getter region 180 formed of calcium (Ca) or a calciumcompound (e.g., CaCO₃), the secondary oxide region 170 formed ofmagnesium oxide (MgO), the free region 120 formed of a CoFeB material,the intermediate oxide region 130 formed of MgO, and the fixed region110 formed at least partially of a CoFeB material. Due to the lower heatof formation of CaO (i.e., −6.58 (eV)) compared to the heat of formationof MgO (i.e., −6.28 (eV)), oxygen from the secondary oxide region 170transfers to the getter region 180. Thus, the getter region 180 includesCa and oxygen, which oxygen is derived from the secondary oxide region170. Moreover, though both the secondary oxide region 170 and theintermediate oxide region 130, of this embodiment, are formed from thesame material, MgO, the secondary oxide region 170 of the resultingmagnetic cell core 101 has a lower concentration of oxygen and a lowerelectrical resistance than the intermediate oxide region 130. Thesecondary oxide region 170 may have an electrical resistance that isless than about 20% that of the intermediate oxide region 130.

Though, in FIG. 1, the getter region 180 is directly adjacent and belowthe secondary oxide region 170, in other embodiments, such as that ofFIG. 2, the getter region 180 may be proximate to the secondary oxideregion 170 by being located internal to a secondary oxide region 270.For example, the getter region 180 may be a central sub-region of thesecondary oxide region 270, with an upper oxide sub-region 276 over thegetter region 180 and a lower oxide sub-region 278 under the getterregion 180. The upper oxide sub-region 276 may be adjacent to the freeregion 120 along interface 272, and the lower oxide sub-region 278 maybe adjacent to the lower electrode 105 or, if present, the lowerintermediary regions 140 along interface 274.

In other embodiments, the getter region 180 may not be a distinctiveregion proximate to (e.g., adjacent to or internal to) the secondaryoxide region 170 (FIG. 1), but may be a region of the getter materialembedded within a material neighboring the secondary oxide region 170.In any respect, the getter material is proximate to the secondary oxideregion 170 and is configured and formulated to remove oxygen from thesecondary oxide region 170 to lower the oxygen concentration and theelectrical resistance of the secondary oxide region 170.

Accordingly, disclosed is a memory cell comprising a magnetic cell core.The magnetic cell core comprises a magnetic region exhibiting aswitchable magnetic orientation. Another magnetic region exhibits afixed magnetic orientation. An intermediate oxide region is disposedbetween the magnetic region and the another magnetic region. Anotheroxide region is spaced from the intermediate oxide region by themagnetic region. The another oxide region has a lower electricalresistance than the intermediate oxide region. A getter region isproximate to the another oxide region and comprises oxygen and a metal.

Forming memory cells of the present disclosure may include sequentiallyforming the material or materials of each region from bottom to top.Therefore, for example, to form the magnetic cell structure 100 of FIG.1, the conductive material of the lower electrode may be formed over thesubstrate 102. Then, the materials of the lower intermediary regions140, if included, may be formed over the conductive material. Then, thegetter material of the getter region 180 may be formed (e.g., bysputtering, CVD, PVD, ALD, or other known deposition technique). Theoxide material of the secondary oxide region 170 may be formed over thegetter material, and the magnetic material of the free region 120 may beformed over the oxide material. The oxide material of the intermediateoxide region 130 may then be formed over the magnetic material of thefree region 120. The magnetic material of the fixed region 110 may beformed over the oxide material of the intermediate oxide region 130. Thematerial of the upper intermediary regions 150, if included, may beformed thereover. Finally, the conductive material of the upperelectrode 104 may be formed. The materials may then be patterned, in oneor more stages, to form the structure of the magnetic cell core 101.Techniques for patterning structures, such as precursor structures ofthe materials described to form structures such as the magnetic cellstructure 100 of FIG. 1, are known in the art and so are not describedin detail.

A magnetic cell structure 200 of FIG. 2 may be similarly formed, withthe exception that formation of the oxide material of the secondaryoxide region 270 may be formed in multiple stages to form the getterregion 180 between the lower oxide sub-region 278 and the upper oxidesub-region 276.

At least after formation of the getter material of the getter region 180and the oxide material of the secondary oxide region (e.g., thesecondary oxide region 170 of FIG. 1, the secondary oxide region 270 ofFIG. 2), oxygen may be transferred (e.g., during an anneal) between thesecondary oxide region (e.g., 170 of FIG. 1, 270 of FIG. 2) and thegetter region 180. With reference to FIG. 3, illustrated is a partialcell core structure 300 in which an oxide material 370, comprisingoxygen 371, is proximate to a getter material 380. FIG. 3 may representthe state of the oxide material 370 and the getter material 380 atinitial formation of the materials. After time and, in some embodiments,after anneal, at least some of the oxygen 371 diffuses from the oxidematerial 370 to the getter material 380, forming, as illustrated in FIG.4, a partial cell core structure 400 having oxide material 470, depletedin oxygen, and getter material 480, enriched in oxygen. At least in someembodiments, some of the oxygen 371 remains in the depleted oxidematerial 470 such that the depleted oxide material 470, remainsformulated and configured to induce MA with the free region 120. Theelectrical resistance of the depleted oxide material 470 (FIG. 4) islower than the electrical resistance of the oxide material 370 (FIG. 3).

One or more anneal stages may be carried out during or after formationof the materials of the magnetic cell core 101. In some embodiments, theanneal may be carried out after patterning.

Though in the embodiments of FIGS. 1 and 2, the free region 120 isillustrated as being closer to the substrate 102 than the fixed region110, in other embodiments, the fixed region 110 may be closer to thesubstrate 102. For example, with reference to FIG. 5, a magnetic cellstructure 500, according to another embodiment of the presentdisclosure, may alternatively include a magnetic cell core 501 thatcomprises, from bottom (proximate to the substrate 102, the lowerelectrode 105, and, if included, the lower intermediary regions 140) totop (proximate to the upper electrode 104 and, if included, the upperintermediary regions 150) the fixed region 110, the intermediate oxideregion 130, the free region 120, and the secondary oxide region 170. Thegetter region 180 may be proximate to the secondary oxide region 170,for example, adjacent and over the secondary oxide region 170 (as inFIG. 5), or internal to the secondary oxide region 170 (as in FIG.secondary oxide region 270 of FIG. 2).

At least after formation of the secondary oxide region 170 and thegetter region 180, oxygen may be transferred from the secondary oxideregion 170 to the getter region 180 to lower the oxygen concentrationand the electrical resistance of the secondary oxide region 170. In theembodiment of FIG. 5, the oxygen is transferred upward.

Accordingly, disclosed is a method of forming a magnetic memory cell.The method comprises forming a free region between an intermediate oxideregion and another oxide region. A getter material is formed proximateto the another oxide region. Oxygen is transferred from the anotheroxide region to the getter material to decrease an electrical resistanceof the another oxide region.

In some embodiments, the secondary oxide region 170 and the getterregion 180 may not be in direct contact. For example, as illustrated inFIG. 6, a partial cell core structure 600 may include an intermediateregion 660 between the secondary oxide region 170 and the getter region180, such that the secondary oxide region 170 contacts the intermediateregion 660 along interface 676. The intermediate region 660 may beformulated to permit diffusion of oxygen from the secondary oxide region170 to the getter region 180. Therefore, even with the secondary oxideregion 170 proximate to, but not directly adjacent to, the getter region180, the proximity of the getter region 180 to the secondary oxideregion 170 may enable the reduction of the oxygen concentration and theelectrical resistance of the secondary oxide region 170.

With reference to FIGS. 7 and 8, in some embodiments, the gettermaterial of a partial cell core structure 700 may be proximate to thesecondary oxide region 170 by being laterally adjacent thereto. Thus, agetter region 780 may laterally surround the secondary oxide region 170and may remove oxygen from and reduce the electrical resistance of thesecondary oxide region 170.

With reference to FIG. 9, illustrated is an STT-MRAM system 900 thatincludes peripheral devices 912 in operable communication with anSTT-MRAM cell 914, a grouping of which may be fabricated to form anarray of memory cells in a grid pattern including a number of rows andcolumns, or in various other arrangements, depending on the systemrequirements and fabrication technology. The STT-MRAM cell 914 includesa magnetic cell core 902, an access transistor 903, a conductivematerial that may function as a data/sense line 904 (e.g., a bit line),a conductive material that may function as an access line 905 (e.g., aword line), and a conductive material that may function as a source line906. The peripheral devices 912 of the STT-MRAM system 900 may includeread/write circuitry 907, a bit line reference 908, and a senseamplifier 909. The cell core 902 may be any one of the magnetic cellcores (e.g., the magnetic cell core 101 (FIG. 1), the magnetic cell core201 (FIG. 2), the magnetic cell core 501 (FIG. 5)) described above. Dueto the structure of the cell core 902, the method of fabrication, orboth, the STT-MRAM cell 914 may include a free region 120 (FIG. 1)between two MA-inducing, oxide regions (e.g., the intermediate oxideregion 130 (FIG. 1) and the secondary oxide region 170 (FIG. 1)) withthe electrical resistance contribution from the secondary oxide region170 being less than about 50% of that of the intermediate oxide region130. Therefore, the STT-MRAM cell 914 may have high MA strength, highmagnetoresistance, a low RA product, and low programming voltage.

In use and operation, when an STT-MRAM cell 914 is selected to beprogrammed, a programming current is applied to the STT-MRAM cell 914,and the current is spin-polarized by the fixed region of the cell core902 and exerts a torque on the free region of the cell core 902, whichswitches the magnetization of the free region to “write to” or “program”the STT-MRAM cell 914. In a read operation of the STT-MRAM cell 914, acurrent is used to detect the resistance state of the cell core 902.

To initiate programming of the STT-MRAM cell 914, the read/writecircuitry 907 may generate a write current (i.e., a programming current)to the data/sense line 904 and the source line 906. The polarity of theprogramming voltage between the data/sense line 904 and the source line906 determines the switch in magnetic orientation of the free region inthe cell core 902. By changing the magnetic orientation of the freeregion with the spin polarity, the free region is magnetized accordingto the spin polarity of the programming current, and the programmedlogic state is written to the STT-MRAM cell 914.

To read the STT-MRAM cell 914, the read/write circuitry 907 generates aread voltage to the data/sense line 904 and the source line 906 throughthe cell core 902 and the access transistor 903. The programmed state ofthe STT-MRAM cell 914 relates to the electrical resistance across thecell core 902, which may be determined by the voltage difference betweenthe data/sense line 904 and the source line 906. Thus, the lowerelectrical resistance of the STT-MRAM cell 914, due to the loweredelectrical resistance of the secondary oxide region 170 (FIG. 1) due tothe getter region 180 (FIG. 1), enables use of a lower programmingvoltage. The STT-MRAM cell 914 may have a higher effectivemagnetoresistance, due to the getter region 180 (FIG. 1), which mayfurther enhance performance of the STT-MRAM cell 914. In someembodiments, the voltage difference may be compared to the bit linereference 908 and amplified by the sense amplifier 909.

FIG. 9 illustrates one example of an operable STT-MRAM system 900. It iscontemplated, however, that the magnetic cell cores (e.g., the magneticcell core 101 (FIG. 1), the magnetic cell core 201 (FIG. 2), themagnetic cell core 501 (FIG. 5)) may be incorporated and utilized withinany STT-MRAM system configured to incorporate a magnetic cell corehaving magnetic regions.

Accordingly, disclosed is a spin torque transfer magnetic random accessmemory (STT-MRAM) system comprising STT-MRAM cells. At least oneSTT-MRAM cell of the STT-MRAM cells comprises a pair of magnetic regionsand a pair of oxide regions. The pair of magnetic regions comprises amagnetic region, exhibiting a switchable magnetic orientation, andanother magnetic region, exhibiting a fixed magnetic orientation. Thepair of oxide regions comprises an intermediate oxide region and anotheroxide region. The intermediate oxide region is between the magneticregion and the another magnetic region. The another oxide region isadjacent a surface of the magnetic region opposite an interface betweenthe intermediate oxide region and the magnetic region. The another oxideregion has a lower electrical resistance than the intermediate oxideregion. The at least one STT-MRAM cell also comprises a getter regionproximate to the another oxide region. The getter region comprises ametal and oxygen. At least one peripheral device is in operablecommunication with the at least one STT-MRAM cell. At least one of anaccess transistor, a bit line, a word line, and a source line are inoperable communication with the magnetic cell core.

With reference to FIG. 10, illustrated is a simplified block diagram ofa semiconductor device 1000 implemented according to one or moreembodiments described herein. The semiconductor device 1000 includes amemory array 1002 and a control logic component 1004. The memory array1002 may include a plurality of the STT-MRAM cells 914 (FIG. 9)including any of the magnetic cell cores (e.g., the magnetic cell core101 (FIG. 1), the magnetic cell core 201 (FIG. 2), the magnetic cellcore 501 (FIG. 5)) discussed above, which magnetic cell cores (e.g., themagnetic cell core 101 (FIG. 1), the magnetic cell core 201 (FIG. 2),the magnetic cell core 501 (FIG. 5)) may have been formed according to amethod described above and may be operated according to a methoddescribed above. The control logic component 1004 may be configured tooperatively interact with the memory array 1002 so as to read from orwrite to any or all memory cells (e.g., STT-MRAM cell 914 (FIG. 9))within the memory array 1002.

Accordingly, disclosed is a semiconductor device comprising a spintorque transfer magnetic random access memory (STT-MRAM) arraycomprising STT-MRAM cells. At least one STT-MRAM cell of the STT-MRAMcells comprises an intermediate oxide region between a free region and afixed region. Another oxide region is adjacent to the free region and isspaced from the intermediate oxide region. The another oxide region hasa lower electrical resistance than the intermediate oxide region. Agetter region is proximate the another oxide region and comprises ametal having a metal-oxide heat of formation that is less than 10%greater than a heat of formation of an oxide of the another oxideregion.

With reference to FIG. 11, depicted is a processor-based system 1100.The processor-based system 1100 may include various electronic devicesmanufactured in accordance with embodiments of the present disclosure.The processor-based system 1100 may be any of a variety of types such asa computer, pager, cellular phone, personal organizer, control circuit,or other electronic device. The processor-based system 1100 may includeone or more processors 1102, such as a microprocessor, to control theprocessing of system functions and requests in the processor-basedsystem 1100. The processor 1102 and other subcomponents of theprocessor-based system 1100 may include magnetic memory devicesmanufactured in accordance with embodiments of the present disclosure.

The processor-based system 1100 may include a power supply 1104 inoperable communication with the processor 1102. For example, if theprocessor-based system 1100 is a portable system, the power supply 1104may include one or more of a fuel cell, a power scavenging device,permanent batteries, replaceable batteries, and rechargeable batteries.The power supply 1104 may also include an AC adapter; therefore, theprocessor-based system 1100 may be plugged into a wall outlet, forexample. The power supply 1104 may also include a DC adapter such thatthe processor-based system 1100 may be plugged into a vehicle cigarettelighter or a vehicle power port, for example.

Various other devices may be coupled to the processor 1102 depending onthe functions that the processor-based system 1100 performs. Forexample, a user interface 1106 may be coupled to the processor 1102. Theuser interface 1106 may include input devices such as buttons, switches,a keyboard, a light pen, a mouse, a digitizer and stylus, a touchscreen, a voice recognition system, a microphone, or a combinationthereof. A display 1108 may also be coupled to the processor 1102. Thedisplay 1108 may include an LCD display, an SED display, a CRT display,a DLP display, a plasma display, an OLED display, an LED display, athree-dimensional projection, an audio display, or a combinationthereof. Furthermore, an RF sub-system/baseband processor 1110 may alsobe coupled to the processor 1102. The RF sub-system/baseband processor1110 may include an antenna that is coupled to an RF receiver and to anRF transmitter (not shown). A communication port 1112, or more than onecommunication port 1112, may also be coupled to the processor 1102. Thecommunication port 1112 may be adapted to be coupled to one or moreperipheral devices 1114, such as a modem, a printer, a computer, ascanner, or a camera, or to a network, such as a local area network,remote area network, intranet, or the Internet, for example.

The processor 1102 may control the processor-based system 1100 byimplementing software programs stored in the memory. The softwareprograms may include an operating system, database software, draftingsoftware, word processing software, media editing software, or mediaplaying software, for example. The memory is operably coupled to theprocessor 1102 to store and facilitate execution of various programs.For example, the processor 1102 may be coupled to system memory 1116,which may include one or more of spin torque transfer magnetic randomaccess memory (STT-MRAM), magnetic random access memory (MRAM), dynamicrandom access memory (DRAM), static random access memory (SRAM),racetrack memory, and other known memory types. The system memory 1116may include volatile memory, non-volatile memory, or a combinationthereof. The system memory 1116 is typically large so that it can storedynamically loaded applications and data. In some embodiments, thesystem memory 1116 may include semiconductor devices, such as thesemiconductor device 1000 of FIG. 10, memory cells including any of themagnetic cell cores (e.g., the magnetic cell core 101 (FIG. 1), themagnetic cell core 201 (FIG. 2), the magnetic cell core 501 (FIG. 5))discussed above, or a combination thereof.

The processor 1102 may also be coupled to non-volatile memory 1118,which is not to suggest that system memory 1116 is necessarily volatile.The non-volatile memory 1118 may include one or more of STT-MRAM, MRAM,read-only memory (ROM) such as an EPROM, resistive read-only memory(RROM), and flash memory to be used in conjunction with the systemmemory 1116. The size of the non-volatile memory 1118 is typicallyselected to be just large enough to store any necessary operatingsystem, application programs, and fixed data. Additionally, thenon-volatile memory 1118 may include a high capacity memory such as diskdrive memory, such as a hybrid-drive including resistive memory or othertypes of non-volatile solid-state memory, for example. The non-volatilememory 1118 may include semiconductor devices, such as the semiconductordevice 1000 of FIG. 10, memory cells including any of the magnetic cellcores (e.g., the magnetic cell core 101 (FIG. 1), the magnetic cell core201 (FIG. 2), the magnetic cell core 501 (FIG. 5)) discussed above, or acombination thereof.

Accordingly, disclosed is an electronic system comprising at least oneprocessor. The at least one processor comprises at least one magneticmemory cell. The at least one magnetic memory cell comprises a fixedregion exhibiting a fixed magnetic orientation, an intermediate oxideregion adjacent to the fixed region, and a free region adjacent to theintermediate oxide region. The free region exhibits a switchablemagnetic orientation. Another oxide region is adjacent to the freeregion, and a getter material is proximate to the another oxide region.The getter material comprises a metal and oxygen. A metal oxide of themetal has a heat of formation that is less than about 10% greater than aheat of formation of an oxide of the another oxide region. A powersupply is in operable communication with the at least one processor.

While the present disclosure is susceptible to various modifications andalternative forms in implementation thereof, specific embodiments havebeen shown by way of example in the drawings and have been described indetail herein. However, the present disclosure is not intended to belimited to the particular forms disclosed. Rather, the presentdisclosure encompasses all modifications, combinations, equivalents,variations, and alternatives falling within the scope of the presentdisclosure as defined by the following appended claims and their legalequivalents.

What is claimed is:
 1. An electronic system, comprising: an intermediate oxide region between a first magnetic region and a second magnetic region; a secondary oxide region adjacent one of the first magnetic region or the second magnetic region and located on an opposite side of the one of the first magnetic region or the second magnetic region than the intermediate oxide region; and a getter region internal to the secondary oxide region.
 2. The electronic system of claim 1, wherein the getter region comprises calcium, strontium, aluminum, barium, zirconium, or compounds thereof.
 3. The electronic system of claim 1, wherein the secondary oxide region comprises an upper oxide sub-region and a lower oxide sub-region, the getter region between the upper oxide sub-region and the lower oxide sub-region.
 4. The electronic system of claim 3, wherein the getter region directly contacts each of the upper oxide sub-region and the lower oxide sub-region.
 5. The electronic system of claim 1, wherein the getter region is physically isolated from the intermediate oxide region.
 6. The electronic system of claim 1, wherein the secondary oxide region comprises the same chemical elements as the intermediate oxide region.
 7. The electronic system of claim 1, wherein the secondary oxide region is electrically conductive.
 8. An electronic system, comprising: a first oxide region between a first magnetic region and a second magnetic region; a second oxide region on a side of one of the first magnetic region or the second magnetic region, the second oxide region having an electrical resistance of less than about 50% of an electrical resistance of the first oxide region; and a getter material on another side of the one of the first magnetic region or the second magnetic region.
 9. The electronic system of claim 8, wherein the getter material comprises calcium and the second oxide region comprises magnesium.
 10. The electronic system of claim 8, wherein the getter material comprises a metal embedded in a carrier material.
 11. The electronic system of claim 10, wherein the carrier material comprises magnesium oxide or titanium oxide.
 12. The electronic system of claim 8, wherein the second oxide region has an electrical resistance within a range from about 1% to about 20% of the electrical resistance of the first oxide region.
 13. The electronic system of claim 8, wherein the getter material comprises magnesium oxide, strontium oxide, aluminum oxide, barium oxide, or zirconium oxide.
 14. The electronic system of claim 8, further comprising a foundation material on a side of the getter region opposite the second oxide region.
 15. The electronic system of claim 14, wherein the foundation material comprises at least one of iron and cobalt.
 16. The electronic system of claim 14, wherein the foundation material comprises tantalum, titanium, ruthenium, tungsten, a metal nitride, or combinations thereof.
 17. A processor-based system, comprising: a processor; and a memory region operably coupled to the processor, the memory region comprising: an intermediate oxide region adjacent a magnetic region; a secondary oxide region adjacent the magnetic region and on a side of the magnetic region opposite the intermediate oxide region; and a getter material surrounding the secondary oxide region.
 18. The processor-based system of claim 17, wherein the getter material has a circular cross-sectional shape.
 19. The processor-based system of claim 17, wherein the magnetic region exhibits a switchable magnetic orientation.
 20. The processor-based system of claim 17, wherein the secondary oxide region comprises magnesium oxide, aluminum oxide, or titanium oxide. 